In the display field, the higher the desired brightness of a display screen is, accordingly, the greater the analog power supply voltage of a source driver chip of a display module must be. Thus, in order to ensure that the display screen can emit light with maximum brightness, the analog power supply voltage of the source driver chip is generally set to the voltage corresponding to the maximum brightness.
However, when the source driver chip operates at a voltage corresponding to the maximum brightness, power consumption of the source driver chip is high.